Four-way parallel short-distance flat wire winding and motor

Abstract

The present invention relates to a four-way parallel short-distance flat wire winding, including a U-phase winding, a V-phase winding and a W-phase winding, and each phase winding includes four branches arranged in parallel, the flat wire winding is arranged in 8 layers in each stator tooth slot, the outlet end of the flat wire winding is located at the welding end, the first branch and the second branch of the four branches are radially fed from the outer layer and the two are wound in a clockwise direction, the third branch and the fourth branch are radially fed from the inner layer and the two are wound in a counterclockwise direction. According to the winding connection method of the present invention, the disadvantages of a high number of series turns per phase, a large heat load, and a fast power drop at high speed existing in the parallel connection of one branch or two branches are avoided, and at the same time, the potential balance can be achieved in the two pairs of poles of each phase, thereby also eliminating the intra-phase circulating current; the overall axial size of the winding is small, and the outlet ends are close to each other, which is convenient for the design of the busbar.

Description

Technical Field

[0001] The invention relates to the technical field of motors, and in particular to a four-way parallel short-distance flat wire winding and a motor. Background Art

[0002] With the development of electric vehicle technology, the performance requirements for electric vehicle drive motors are getting higher and higher, and the power density of drive motors is constantly increasing. There are gaps between the outer circles of existing enameled round copper wires, which limits the improvement of slot fill rate and can no longer meet the performance requirements of current automotive motors. Compared with round windings, flat wires are first made into a hairpin-like shape, then inserted into the stator slots, and then passed out from the other end, and the ends of the hairpins are welded. At present, the flat wire technology in the automotive industry is relatively mature with 4 / 6 / 8 / 10-layer flat wire designs, but most motors have only 1 or 2 parallel stator windings. Excessive turns make it difficult to increase high-speed power. In order to increase power while ensuring efficiency, multi-parallel design becomes an inevitable choice. For multi-parallel, its winding method needs to be redesigned, and this also requires consideration of how to set it to avoid intra-phase circulation. However, the design of the winding method requires comprehensive consideration of multiple factors. In addition to meeting electrical performance, it is also necessary to consider the specifications and quantity of conductor components, manufacturing process, and manufacturing process of the busbar connected to the winding. Currently, there is no flat wire stator winding that can eliminate the intra-phase circulating current on the basis of four-way parallel connection. Summary of the invention

[0003] To this end, the present invention proposes a four-way parallel short-distance flat wire winding and a motor, and the specific scheme is as follows.

[0004] A four-way parallel short-distance flat wire winding comprises a U-phase winding, a V-phase winding and a W-phase winding, and each phase winding comprises four branches arranged in parallel, the flat wire winding is arranged in 8 layers in each stator tooth slot, the outlet end of the flat wire winding is located at the welding end, the first branch and the second branch of the four branches are radially fed from the outer layer and the two are wound in a clockwise direction, the third branch and the fourth branch are radially fed from the inner layer and the two are wound in a counterclockwise direction.

[0005] According to one aspect of the present invention, for the U-phase winding, the incoming slot of the second branch is located at the first slot after the incoming slot of the first branch in the counterclockwise direction, the incoming slot of the fourth branch is located at the first slot after the incoming slot of the third branch in the clockwise direction, and the incoming slot of the first branch is the same as the incoming slot of the third branch.

[0006] According to one aspect of the present invention, the slot number of the incoming slot of the V-phase winding differs by 4 from that of the U-phase winding in the counterclockwise direction, and the slot number of the incoming slot of the W-phase winding differs by 4 from that of the V-phase winding in the counterclockwise direction.

[0007] According to one aspect of the present invention, there are four cycles in the four branches of each phase winding; in each phase winding, for its four cycles, the span variation mode in each cycle is the same; for the four branches, the span variation mode in each cycle is different.

[0008] According to one aspect of the present invention, in the first branch, the span variation in each cycle is 6-7-6-5-6-7-6;

[0009] In the second branch, the span changes in each cycle are 6-5-6-7-6-5-6;

[0010] In the third branch, the span changes in each cycle are 7-6-5-6-7-6-5;

[0011] In the fourth branch, the span changes in each cycle are 5-6-7-6-5-6-7.

[0012] According to one aspect of the present invention, in the first branch, the spans between the cycles are 5-4-5 in sequence;

[0013] In the second branch, the spans between the cycles are 7-6-7;

[0014] In the third and fourth branches, the spans between the cycles are 6-5-6 respectively.

[0015] According to one aspect of the present invention, in the first branch and the second branch, the number of layers in each period changes alternately between 2n-1 and 2n, where n is the number of periods.

[0016] According to one aspect of the present invention, in the third branch and the fourth branch, the number of layers in each period changes alternately between 10-2n and 9-2n, where n is the number of periods.

[0017] The present invention also provides a motor, comprising a rotor assembly and a stator assembly, wherein the stator assembly has the above-mentioned four-way parallel short-distance flat wire windings.

[0018] The present invention also proposes an electric drive system, comprising at least one of a reducer and an inverter, and the above-mentioned motor.

[0019] As can be seen from the above, the present invention proposes a four-way parallel short-distance flat wire winding, which has the following advantages:

[0020] (1) The four-way parallel connection avoids the disadvantages of a high number of series turns per phase, a large heat load, and a rapid power drop at high speeds that exist in the connection of one branch or two branches in parallel. At the same time, the potential balance can be achieved in the two pairs of poles of each phase, thereby eliminating the intra-phase circulating current.

[0021] (2) The outlet side and the welding side are on the same side, which can reduce the axial length of the motor and save space;

[0022] (3) The outlet terminals are close to each other, which facilitates the design of the bus.

[0023] Other features and advantages of the present invention will be described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Exemplary embodiments of the present invention are described with reference to the accompanying drawings, in which:

[0025] Figure 1 A perspective view of a stator assembly according to an embodiment of the present invention is shown.

[0026] Figure 2 The nomenclature of the tooth grooves and layer numbers is shown schematically.

[0027] Figure 3 The expanded design diagram of the stator winding of the present invention is shown.

[0028] Figure 4 The U-phase development design diagram of the stator winding of the present invention is shown.

[0029] Figure 5 The V-phase development design diagram of the stator winding of the present invention is shown.

[0030] Figure 6 The W-phase development design diagram of the stator winding of the present invention is shown.

[0031] All the drawings are only schematic and not necessarily drawn to scale, and they only show those parts necessary for explaining the present invention, and other parts are omitted or only mentioned. That is, in addition to the parts shown in the drawings, the present invention may also include other parts.

[0032] In the figures, identical and / or functionally identical technical features are provided with identical or similar reference numerals. DETAILED DESCRIPTION

[0033] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, many specific details are set forth so that those skilled in the art can more fully understand and implement the present invention. However, it will be apparent to those skilled in the art that the present invention may be implemented without some of these specific details. In addition, it should be understood that the present invention is not limited to the specific embodiments described. On the contrary, any combination of the features and elements described below may be considered to implement the present invention, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments and advantages are intended for illustration purposes only and should not be considered as features or limitations of the claims unless explicitly stated in the claims.

[0034] In the following description, the descriptions about directions, such as "upper", "lower", "inner", "outer", "radial", "axial", etc., which may be used, are only for the convenience of description, unless otherwise specified, and are not intended to form any limitation on the technical solution of the invention. In addition, in the following description, terms such as "first", "second", etc. are used to describe the elements of the present application, and these terms are only used to distinguish the elements, and are not intended to limit the nature, sequence, order or number of these elements.

[0035] Figure 1 FIG. 1 shows a three-dimensional view of a stator assembly according to an embodiment of the present invention. The stator assembly includes a stator core 1 and a stator winding 2. Figure 1 It can be seen from the figure that the outlet end of the stator winding is designed at the welding end. In addition, the stator winding of the present invention is made of U-pin only.

[0036] Furthermore, the stator core 1 of the present invention has 48 stator slots, and 8 layers of conductors are arranged in each stator slot. Figure 2 As shown. Figure 2 In the embodiment, the stator slots are numbered in a counterclockwise direction, and the layer numbers in the stator slots are numbered from the 1st layer to the 8th layer from the outside to the inside in the radial direction or from the inside to the outside in the slots.

[0037] The following combination Figure 3-Figure 6 The design of the stator winding of the present invention is described in detail.

[0038] In the present invention, the stator winding includes a U phase, a V phase and a W phase, and each phase winding adopts a four-way parallel connection mode. As an important improvement of the present invention, the present invention, while adopting a four-way parallel winding design, also enables the winding to form a potential balance in the two pairs of poles of each phase winding, thereby eliminating the intra-phase circulating current. Therefore, the problem of intra-phase circulating current is solved, and the defect of low parallel branch number does not exist.

[0039] Specifically, since a three-phase winding is used, the connection relationship of each phase winding is the same, and the only difference is the starting position. In the embodiment to be described below, the V-phase incoming line is separated from the U-phase incoming line by 4 tooth slots, and the W-phase incoming line is separated from the V-phase incoming line by 4 tooth slots. This can be seen from Figure 3 As can be seen from the winding expansion diagram shown, the slot number of the V-phase winding's incoming slot differs by 4 in the counterclockwise direction from that of the U-phase winding's incoming slot, and the slot number of the W-phase winding's incoming slot differs by 4 in the counterclockwise direction from that of the V-phase winding's incoming slot.

[0040] Taking the U phase as an example, it includes 4 branches, namely U1, U2, U3 and U4. For the first branch U1, it has an incoming line segment U1_in and an outgoing line terminal U1_out. The winding method between the incoming line segment U1_in and the outgoing line terminal U1_out is as follows:

[0041] U1_in→1(1)→43(2)→36(1)→30(2)→25(1)→19(2)→12(1)→6(2)→1(3)→43(4)→36(3)→30(4)→25(3)→19(4)→12(3)→6(4)→ 2(5)→44(6)→37(5)→31(6)→26(5)→20(6)→13(5)→7(6)→2(7)→44(8)→37(7)→31(8)→26(7)→20(8)→13(7)→7(8)→U1_out.

[0042] From the above, we can see that in this branch, there are 4 periods in total, and in each period, the number of layers where the conductor is located alternates between two adjacent layers. Taking the first period as an example, in this period, the number of layers of the conductor alternates between 1 and 2. In the second period, it alternates between 3 and 4 accordingly. In addition, combined with Figure 2 , the winding method of the first branch is clockwise.

[0043] In this branch, in each winding cycle, there are three span modes, namely the first span, the second span and the third span. Among them, the difference between the maximum and the minimum of the three spans does not exceed 2. In addition, the span change mode in each cycle is the same. Specifically, in this branch, the span change mode in each cycle is 6-7-6-5-6-7-6.

[0044] In this branch, when entering from one winding cycle to the next winding cycle, the spans are 5, 4, and 5 respectively.

[0045] In this branch, as shown in the above example, the wire is inserted in 1 slot and 1 layer. Obviously, as long as the above winding method is met, such as the law of layer number change, span change, etc., the wire can be inserted in any other slot, and the positions of other conductor elements can be changed accordingly.

[0046] In the second branch, in coordination with the exemplary winding of the first branch described above, the winding of U2 is as follows:

[0047] U2_in→48(1)→42(2)→37(1)→31(2)→24(1)→18(2)→13(1)→7(2)→48(3)→42(4)→37(3)→31(4)→24(3)→18(4)→13(3)→7(4) →1(5)→43(6)→38(5)→32(6)→25(5)→19(6)→14(5)→8(6)→1(7)→43(8)→38(7)→32(8)→25(7)→19(8)→14(7)→8(8)→U2_out.

[0048] As a specific example, the U2 branch enters the 48th slot. However, the specific entry position can be changed. In actual winding, the entry positions of the first branch U1 and the second branch U2 are separated by one slot and meet the following rules:

[0049] In each cycle, the number of layers of the conductor alternates between two adjacent layers. Taking the first cycle as an example, in this cycle, the number of layers of the conductor alternates between 1 and 2. In the second cycle, it alternates between 3 and 4. In addition, combined with Figure 2 , the winding method of the first branch is clockwise.

[0050] In this branch, there are only three span modes, namely the first span, the second span and the third span. Among them, the difference between the maximum and the minimum of the three spans does not exceed 2. In addition, the span change mode in each cycle is the same. Specifically, in this branch, the span change mode in each cycle is 6-5-6-7-6-5-6. In this branch, when entering the next winding cycle from one winding cycle, the spans are 7, 6, and 7 respectively.

[0051] For the third branch, the winding method is as follows:

[0052] U3_in→1(8)→8(7)→14(8)→19(7)→25(8)→32(7)→38(8)→43(7)→1(6)→8(5)→14(6)→19(5)→25(6)→32(5)→38(6)→43(5)→4 8(4)→7(3)→13(4)→18(3)→24(4)→31(3)→37(4)→42(3)→48(2)→7(1)→13(2)→18(1)→24(2)→31(1)→37(2)→42(1)→U3_out

[0053] As can be seen from the above, the third branch no longer enters from the lower layer, but from the upper layer. This branch is also divided into 4 winding cycles, but in the first cycle, the number of layers changes from 8-7-8-7-8-7-8-7. The number of layers from the second to the fourth cycle changes alternately between 10-2n and 9-2n according to the number of cycles they are in.

[0054] The winding of the third branch is carried out in a counterclockwise manner, which is combined with its tooth number. Figure 2 It can be seen.

[0055] In the third branch, there are three span modes, namely the first span, the second span and the third span. Among them, the difference between the maximum and the minimum of the three spans does not exceed 2. In addition, the span change mode in each cycle is the same. Specifically, in this branch, the span change mode in each cycle is 7-6-5-6-7-6-5.

[0056] In this branch, when entering from one winding cycle to the next winding cycle, the spans are 6, 5, and 6 respectively.

[0057] The cable entry duct of the third branch is the same as the cable entry duct of the first branch.

[0058] For the fourth branch, the matching winding method is as follows, which is consistent with the examples of the first branch to the third branch mentioned above:

[0059] U4_in→2(8)→7(7)→13(8)→20(7)→26(8)→31(7)→37(8)→44(7)→2(6)→7(5)→13(6)→20(5)→26(6)→31(5)→37(6)→44(5)→ 1(4)→6(3)→12(4)→19(3)→25(4)→30(3)→36(4)→43(3)→1(2)→6(1)→12(2)→19(1)→25(2)→30(1)→36(2)→43(1)→U4_out.

[0060] From the above, we can see that the fourth branch enters from slot 2 and also from the upper layer, and the winding direction is counterclockwise. However, the specific winding method of the fourth branch does not have to follow the above description, as long as it differs from the entry slot of the third branch by one and meets the following winding concerns.

[0061] In terms of the number of layers, the variation pattern of the number of layers is the same as that of the third branch. In terms of span, there are also three span modes, namely the first span, the second span and the third span. Among them, the difference between the maximum and the minimum values ​​of the three spans does not exceed 2. The span variation mode in each cycle is the same. In this branch, when entering the next winding cycle from one winding cycle, the spans are 6, 5, and 6 respectively.

[0062] The difference from the third branch is that in the fourth branch, the span changes in each cycle are 5-6-7-6-5-6-7.

[0063] According to the winding method described above, calculations show that for each phase branch, potential balance can be achieved in the two pole pairs of the winding, so there is no potential difference, and no current will be generated. Therefore, while using a high number of parallel branches, the intra-phase circulating current is eliminated.

[0064] Likewise, combining Figure 3 Through calculation, it can be found that at the welding end, all the outlet terminals are located within a range of less than 180° in the circumferential direction, so this is also beneficial to the design of the busbar.

[0065] In addition, the outgoing line side and the welding side are on the same side, which can reduce the axial length of the motor and save space.

[0066] The motor with the stator winding of the present application can be applied to various types of electric vehicles, for example, it can be applied to pure electric vehicles that are only powered by batteries, or it can be applied to hybrid vehicles that are equipped with other types of power sources in addition to the motor.

[0067] The present invention has been clearly and completely described with reference to the above exemplary embodiments, and it should be understood by those skilled in the art that various other embodiments can be conceived by modifying the disclosed technical solutions without departing from the spirit and scope of the present invention. These embodiments should be understood to fall within the scope of the present invention determined based on the claims and any equivalent technical solutions thereof.

Claims

1. A four-way parallel short-distance flat wire winding, comprising a U-phase winding, a V-phase winding and a W-phase winding, wherein each phase winding comprises four branches arranged in parallel, wherein the flat wire winding is arranged in 8 layers in each stator tooth slot, characterized in that: The outlet end of the flat wire winding is located at the welding end. The first branch and the second branch of the four branches are radially fed from the outer layer and are wound in a clockwise direction. The third branch and the fourth branch are radially fed from the inner layer and are wound in a counterclockwise direction.

2. The four-way parallel short-distance flat wire winding according to claim 1, characterized in that: For the U-phase winding, the incoming slot of the second branch is located at the first slot after the incoming slot of the first branch in the counterclockwise direction, the incoming slot of the fourth branch is located at the first slot after the incoming slot of the third branch in the clockwise direction, and the incoming slot of the first branch is the same as the incoming slot of the third branch.

3. The four-way parallel short-distance flat wire winding according to claim 2, characterized in that: The slot number of the incoming slot of the V-phase winding differs by 4 in the counterclockwise direction from that of the incoming slot of the U-phase winding, and the slot number of the incoming slot of the W-phase winding differs by 4 in the counterclockwise direction from that of the incoming slot of the V-phase winding.

4. The four-way parallel short-distance flat wire winding according to any one of claims 1 to 3, characterized in that: There are four periods in the four branches of each phase winding; in each phase winding, for its four periods, the span variation mode in each period is the same; for the four branches, the span variation mode in each period is different.

5. The four-way parallel short-distance flat wire winding according to claim 4, characterized in that: In the first branch, the span changes in each cycle are 6-7-6-5-6-7-6; In the second branch, the span changes in each cycle are 6-5-6-7-6-5-6; In the third branch, the span changes in each cycle are 7-6-5-6-7-6-5; In the fourth branch, the span changes in each cycle are 5-6-7-6-5-6-7.

6. The four-way parallel short-distance flat wire winding according to claim 5, characterized in that: In the first branch, the spans between cycles are 5-4-5; In the second branch, the spans between the cycles are 7-6-7; In the third and fourth branches, the spans between the cycles are 6-5-6 respectively.

7. The four-way parallel short-distance flat wire winding according to any one of claims 1 to 6, characterized in that: In the first branch and the second branch, the number of layers in each period changes alternately between 2n-1 and 2n, where n is the number of periods.

8. The four-way parallel short-distance flat wire winding according to any one of claims 1 to 6, characterized in that: In the third and fourth branches, the number of layers in each period changes alternately between 10-2n and 9-2n, where n is the number of periods.

9. An electric motor, comprising a rotor assembly and a stator assembly, wherein the stator assembly has a four-way parallel short-distance flat wire winding according to any one of claims 1 to 8.

10. An electric drive system, comprising at least one of a reducer and an inverter, characterized in that: Also included is the motor according to claim 9.

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